DiskOnChip 2000 problems

Greetings:

Some DiskOnChip architectural and installation questions:

I purchased a DoC2000 96MB high-profile DIP from a third party; it is installed in a PC-104 Aaeon SSD-2000 module. The Aaeon board has very little documentation and what there is seems to differ from reality, for example selecting DoC #1's 8k address window as D000 using the DIP switch results in data appearing at D200 and it seems that after power-on-reset, the user must write to the board's I/O base register to select one of 16 64k windows (used with SRAM, but seemingly necessary for DoC also) or invalid data appears in the 8k window. Using msdos 'debug', one can write 'FF' to the I/O base register and a valid '55 AA' signature appears at 'D200:0'. If one reboots the CPU at this point, the BIOS scan finds the 'ROM' code but hangs since it isn't a legitimate boot loader from my inspection of the disassembly.

Inspection of the entire 8k window confirms a working DoC device according to the M-Systems specs; there is a repeating 64 byte (1st half) boot record for the first

2k followed by a repeating 64 byte (2nd half) boot record for the next 2k followed by all zeros for the next 4k assuming the device is in 'reset mode'.

Running 'dinfo.exe' against this system (when '55 AA' is readable at the start of the window) shows 'no DiskOnChip devices found'. Note that there are no identification strings of any kind in the boot (IPL) records on this device.

Running 'dformat.exe' against this system produces the same error message.

What conditions are necessary for the utilities to recognize a valid DoC device?

How can one replace the IPL code when the device is not recognized by the utilities? Writing to the IPL area is discussed in the DoC SDK API documentation for low-level services; I don't have the SDK, (would like to find it) and hope that sinking time into custom development isn't necessary just to reprogram a device.

I would appreciate replies from anyone with DoC experience; surely this must have happened to other folks.

TIA,

Michael

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The DiskOnChip module itself is working; I installed it on an ISA SMC8000 Ethernet NIC in the bootrom socket which I modified to connect pin 31 to B11 of the ISA connector. I was able to fdisk, format, install a system and boot from the device.

In 'debug', I cannot see any difference between the PC-104 SSD-2000 installation and this kludged one when inspecting the memory window data; I suppose the next step would be attaching a logic analyzer to the bus but before doing this can anyone relate any experiences in dealing with Aaeon components or communicating with the company? Support for this product is absent from their website and the product name and board silkscreen codes produce no hits in their search engine.

Regards,

Michael

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The only thing I can add is that that you must be able to write to the DOC before it will boot. Is it possible that the Aaeon board is write-protecting that socket?

Reply to
Jim Stewart

In Re: Doc 2000 not working on Aaeon SSD-2000

The Aaeon documentation says to write any value to the base i/o addr+1 of the board, which I have done, to unprotect it ; there are also DIP switches to unprotect various windows which I have tried.

Since I have a working kludge (on the ISA NIC); I can scope pin 31 (/WR) on the DoC during boot as a reference (and look at it on the Aaeon for comparison). I suppose in a pinch could reroute that pin directly to /SMEMW (B11) on the bus but why have the Aaeon board then at all?

I am beginning to suspect that this board was OEM for some special application if in fact it is not defective and its behavior is intentional.

Thanks for the tip,

Michael

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